Amy works for a company that produces plastic lids and cups for restaurants. She wants to estimate what proportion of lids produced in a day have a defect that makes them not fit the cups. She takes a random sample of 250 250250 lids from the more than 10 , 000 total lids produced that day and finds 15 lids in the sample with this defect. Based on this sample, calculate the 99% confidence interval for the proportion of lids produced that day with this defect?

Respuesta :

Answer:

99% confidence interval for the proportion of lids produced that day with this defect somewhere between ( .0213 ,  .0987) or between [tex]2.13\%[/tex] to [tex]9.87\%[/tex]

Step-by-step explanation:

Given -

Sample size ( n) = 250

Sample proportion [tex](\widehat{p})[/tex] = [tex]\frac{15}{250}[/tex] = .06

[tex]\alpha = 1 -[/tex] confidence interval = 1 - .99 = .01

[tex]z_{\frac{\alpha}{2}}[/tex] = [tex]z_{\frac{.01}{2}}[/tex] = 2.58

99% confidence interval for the proportion of lids produced that day with this defect = [tex]\widehat{p} \pm z_{\frac{\alpha}{2}} \sqrt{\frac{(\widehat{p}) (1 - \widehat{p}) }{n}}[/tex]

            =  [tex].06 \pm z_{\frac{.01}{2}} \sqrt{\frac{(.06) (1 - .06) }{250}}[/tex]

             = [tex].06 \pm 2.58\times .0150[/tex]

             = [tex].06 \pm .0387[/tex]

              = ( .06 + .0387 ) ,  ( .06 - .0387 )

              =   ( .0987 , .0213 )

Answer:

(0.021,0.099)

Step-by-step explanation:

khan